Spray booth



Jan. 7, 1941. E BATES 2,227,481

SPRAY BOOTH Filed Oct. 11, 1937 2 Sheets-Sheet l 7, 1941. L. E. BATES 2,227,481

SPRAY Boom Filed Oct. 11, 1937 2 Sheets-Sfieet 2 iii] Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE Luther E. Bates, Chicago, Ill.

Application October 11, 1937, Serial No. 168,322

8 Claims.

My invention relates to a spray booth and has particular reference to a booth in which the application of paint in spray form can be made, and in which the excess spray, which is now allowed to pass out into the atmosphere in many cases, is withdrawn and passed through'a combustion chamber where all solid matter carried in suspense in the spray is burned, thereby removing it from the air, which is then forced into the surrounding atmosphere in a clean condition.

Another and further object of my invention is the provision of a spray booth in which the particles of point suspended in the air, including the air, are withdrawn from the booth and passed through an-incinerating chamber where the mixture is subjected to the action of a flame, thereby removing the particles of paint, gases, and the like. suction fan and forced out into the atmosphere in a cleaned condition without carrying with it any of the particles of paint, coloring matter and foreign substances to become lodged upon various objects in the neighborhood of the painting plant and causing damage to such objects.

Another and further object of my invention is the provision of a spray booth in which a supply of heated, cleaned air is caused to pass through the booth, thereby insuring that the particles of paint and gases are withdrawn into this stream of air and subjected to the action of the flame in the incineratlng chamber, insuring a complete cleaning of the air bearing particles of paint and its removal from the air before it is forced into the atmosphere.

Another and further object of my invention is the provision of a spray booth in which a heated current of air is caused to pass through a filter, thereby removing all particles of dust and dirt therefrom, and impinged against baffles so that all of the particles are impinged against the bailles and taken out of the air stream so that the air which is forced through the spray'boothwill be clean and not carry with it particles of dust, dirt and other matter which lodges upon the freshly painted surfaces of articles to which the paint is applied, spoiling the paint job.

Another and further object of my invention is the supplying of heated air to the spray booth which assists in securing a uniform spread of paint upon the surface to be painted, and in which solid particles of paint in suspension are readily absorbed in the current of heated air and the mass rendered more easy of combustion than if the air stream were cold.

These and other objects of my invention will be more fully and better understood by reference to the accompanying sheets of drawings, and in which- Figure 1 is a vertical, longitudinal sectional The air is then withdrawn by means of a view through a spray booth and the various operating parts thereof;

Figure 2 is a horizontal sectional view on line 2-2 of Figure 1; and

Figure 3 is a vertical, sectional view along line 5 3-3 of Figure 1.

Referring now specifically to the drawings, and in which like reference characters refer to like partsthroughout, a spray booth II) is shown having a roof portion l I, a back. wall I2, a front wall l3 and one end wall ll, the booth being open at one of. its ends to allow for the entrance of workmen with mechanisms for applying the paint and also to place in the booth articles to which the paint is applied. The booth has a floor I5 which may be utilized or omitted if desired, the ordinary floor of a building or the like being substituted in place of this floor.

An exhaust pipe I6 extends through the back wall 12 centrally thereof in a longitudinal direction and is spaced from the floor a suitable distance so that the air is drawn substantially from the center of the booth. The exhaust pipe l6 discharges into a second pipe II which acts as a combustion chamber and which has an enlarged section l8 adjacent the discharge end of the pipe 16 within which a flame spreader i9 is mounted on a suitable bracket 20. The spreader H has a convex face of somewhat less diameter than the section l8 of the combustion pipe l1 so that air, gases and the like, passing therethrough must pass around the edges of the spreader l9.

Mounted in the exhaust pipe I6 is a burner 2! which is connected to a fuel supply pipe 22 leading to any suitable source of fuel such as gas, oil or the like, and having its upper end directed toward the flame spreader l9 so the flame from the burner 2| is impinged against the spreader IS. The fuel is conducted to the burner 2| through pipe 22 and is ignited at the end of the burner 2| and the flame impinged against the spreader plate 19, passing there around where it becomes mingled with the gases which pass from the spray booth Ill, and into the combustion pipe I! where combustion of the mixture takes place.v

The combustion pipe l1 discharges into a stack 23 in the lower end of which a fan 24 is mounted journaled in suitable brackets 25 and 26, supported upon a frame 21. The frame in turn supports a motor 28 mounted on the outer end of the frame and connected to a driving pulley 29 mounted on the outer end of the fan shaft 32 by means of a belt 3| which is connected to the pulley on the shaft of the motor 28. The fan 24 is an exhaust fan and serves to exhaust the air from the spray booth l0 through the exhaust pipe l6 and combustion chamber l1 into the discharge stack 23 which leads to the atmosphere, thereby conveying the air, burned gases and other impuri- 60 At the rear of the booth l0 an intake member 32 is provided which is open at its lower end and through which the combustion member I! extends. -The combustion member l'l extends across the lower end of the intake member 32 and serves to heat the air which is drawn into the lower end of the member 32. ,The member 32 has a roof portion 33 which extends across above the roof ll of the spray booth and spaced therefrom, and thence downward whereby air drawn in at the lower en of the member 32 is discharged into the spray booth I0. An inclined wall 34 connects with one of the walls of the member 32-.

and-with the edge of the roof ll of the spray booth to form a closure for the conduit through which the air passes.

Mounted immediately over the discharge pipe I6 is a receptacle 35 within which a quantity of oil 36 is provided. Positioned'within this receptacle 35 is a lower roller 31 and an upper roller 38, with an endless screen 39 passing over the upper and lower rollers and through the oil 38, this screen being manually operated so that from time to time it can be moved so that the air passing through the intake member 32 must pass through the screen 39 where the initial step in the cleaning operation commences. A filler 40 is provided which is secured to the roof 33 so that the air must pass through the screen 39.

Extending across the area from the roof H of the spray booth to the roof 33 of the intake member 32 is a series of bafiles 4|, 4| suitably mounted on vertical support members 42 placed in the intake member and supported by the roof II and the side walls of the member 32. Mounted on the root His a motor 43 connected'to a fan 44, the fan 44 being mounted adjacent a partition 45 which extends downward. An opening 46 is provided in the partition 45 adjacent the fan 44 through which the.air enters as it is forced to the fan 44 and farther along the intake member 32 to the discharge end 41 of the intake member 32 and into the spray booth Ill. The discharge end 41 of the member 32 is curved so as to direct the air discharged therefrom toward the entrance of the exhaust pipe Hi. In this manner the air is drawn in by the fan 44 into the lower end of theintake member '32, is heated as it passes aroundthe combustion chamber I1, and then passes through the filter screen 39 against the baiiles 4| where additional particles of dirt. dust and the like. are lodged, and finally through the fan 44 and into the spray boothwhere it is withdrawn by the suction of the fan 24 from the spray booth, carrying with it particles of paint, gas and other foreign matter into the burner where the paint, combustible portions of the gas, and the' like are burned and the air forced out intothe atmosphere.

From the foregoing description the operation of the device will be clearly understood, in that the fuel discharged to the burner 2| is lighted, causing a flame to be impinged against the spreader l9. Proper current is supplied to the motors 28 and 43 which'in turn causes a supply of air to be drawn in through the intake 32, through the oil screen 39, and discharged into the booth l0 where it is withdrawn in the manner heretofore described. When the spray booth is in operation, the workmen enter-the booth with the articles to be painted and the paint is applied by means of spray nozzles. The particles of paint which are not impinged against the article being tiesaway from the spray boothand to the atmosphere.

withdrawn and burned as they pass through the discharge pipe and into the combustion chamber. In addition to keeping pure air supplied, the workmen in the booth are supplied with air which is pure for breathing pulposes, and the air which is drawn through the booth is kept clean for the purpose of insuring the painted surfaces not having dirt and dust adhere to them during the application of the paint.

From the foregoing description it will be seen that the present invention contemplates a spraying cabinet employing a booth of the type for instance, in which the front is open for ingress and egress of operatives, while the side walls are substantially closed; it provides this spraying cabinet with means whereby the booth is efliciently scavenged of its vapors in general and its unprecipitated spray liquid in particular, as fast as they accumulate, and consumes at least the combustible constituents of these vapors to avoid contamination of the environment in which the work is performed; its scavenging or vapor disposing means contributes heat to the atmosphere of the booth, that promotes spreadingof the spray-materials upon the work and insures.

efliciency in the vehicular function of the scavenging air; and for accomplishing these sev'- which is of simple, light and economical construca tion. scavenging atmosphere, preferably in warm state, is supplied by the cabinet, to its booth, at a relatively high point through one confined of the booth, and air ladened with vapors, spray, etc., is withdrawn from the booth laterally through means of an exhaust pipe that extends through a. side wall of the booth remote from the point of supply and at an intermediate level of the booth that is sufficiently below the top of the booth to maintain a livable atmosphere for the operative; sufiiciently above the bottom to catch the contaminating elements before they become precipitated; and so related generally to the point of warm air supply as to insure a distribution of the warm air that maintains spreading temperature of the spray and absence of cooling eddy currents that would deteriorate the work. The laterally exhausting intermediately located scavenging pipe'has in line of flow there with, in close proximity to the booth, a combustion chamber of special construction that provides a heater in a comparatively low part of the cabinet; andthe scavenging medium delivered to the booth is fresh airirom an external source, en-

tering below said heater, through ,an upwardly.

screen, which (when one is used)v is of the oil carrying type, in position to intersect the line of flow of the incoming scavenging air after the air has become heated, so that heat from the air will keep the oil on'the screen in efllcient condition to cause adherence to the screen of foreign matter borne in suspension upon the air. The delivery oi the new warmed and screened air into the booth, being at a point substantially at the top of the booth and nextto that one of the closed sides of the booth which is opposite to or remote from the intermediately positioned exhaust pipe, insures 'efiiciency in the distribution, heating effect, and scavenging already alluded to. The combustion feature of the apparatus preferably involves a. burner such as shown at 2| discharging coaxially and in ejecting relation to the exhaust pipe l6; and the flame from this burner impinges against the convex face of the deflector plate or flame spreader i9. ,Defiector I9 is positioned substantially crosswise of the line of flow through exhaust pipe Hi. It is located in enlargement i8. It is preferably not materially less in diameter than exhaust pipe l6 where the latter merges with enlargement l8, and thereby insures against escape of paint ladened air with out first impinging against said disk and being prepared for fire treatment thereby. The burner delivers its burning fuel centrally against the disk and causes it to mingle with the paint ladened air. The disk is suiliciently less in diameter than the inside dimension of the enlargement to leave a space in the enlargement in which combustion may be initiated. Pipe ll which continues the scavenging and fire-treating flue rearwardlyfrom the enlargement and provides space in which combustion may continue to completion, has a diameter that is materially less than that of the enlargement and about equal to that of the deflector, and merges with the enlargement through the mediumlof an abrupt ofiset near which the deflector stands in a manner to introduce a circuitous deflection in the passage that promotes commingling combustion of fuel and paint ladened air, which is depended upon to reduce the product of scavenging to inoffensive flue gases and dust.

While I have described more or less precisely the details of construction, I do not wish to be understood as limiting myself thereto, as I con template changes in form and the proportion of parts and the substitution of equivalents as circumstances may suggest or render expedient Without departing from the spirit or scope of my invention.

I claimzl l. A spray cabinet comprising, in combination, an enclosure member having one open wall, an exhaust pipe leading therefrom, a combustion chamber, an exhaust fan, an intake conduit having the combustion chamber therein, a burner in said combustion chamber having its fuel discharge end parallel with the longitudinal axis of the combustion chamber, a flame spreader adjacent the burner, surrounded by the combustion chamber Wall with a space between the perimeter of said spreader and said chamber Wall; said spreader causing flame from the burner to substantially fill said space; and a suction fan in said intake conduit.

2. A spray cabinet comprising, in combination, an enclosure member having one open wall, an

..exhaust pipe leading therefrom, a combustion iii chamber, an exhaust fan, an intake conduit having the combustion chamber therein, a burner in said combustion chamber, a deflector plate opposite the end of the burner, a suction fan in said intake conduit, and means in the path of air taken into said intake conduit whereby solid particles are removed therefrom.

3. A spray cabinet comprising, in combination, an enclosure member having an open wall, an exhaust pipe leading therefrom, a combustion chamber into which the exhaust pipe leads, a burner in said combustion chamber, an exhaust fan at the end of the combustion chamber, an air intake having its intake end adjacent the combustion chamber and extending therearound and its discharge end in said enclosure, a fan in said intake, 2. screen extending across the intake, and a container into which one end of the said screen extends.

4. A spray cabinet comprising, in combination, an enclosure member having an open wall, an exhaust pipe leading therefrom, a combustion chamber into which the exhaust pipe leads, a burner in said combustion chamber, an exhaust an at theend of the combustion chamber, an air intake having its intake end adjacent the combustion chamber and extending therearound and its discharge end in said enclosure, a fan in said intake, an endless screen extending across the said intake, a container into which the lower end of the screen extends, and baflie means against which the air passing through the said screen is impinged.

5. A spray booth comprising, in combination, an enclosure having side walls and one end wall and a roof, an exhaust pipe leading through one side Wall, a combustion chamber into which the exhaust pipe leads, a burner in said combustion chamber, a flame baffle adjacent the end of the burner surrounded by the wall of said combustion chamber with a space between the perimeter of said fiame-bafile and said wall and causing the flame from the burner to substantially fill said space, an exhaust fan at the end of the combustion chamber, an air intake extending around the combustion chamber at one side of the said enclosure and extending across the roof thereof with its discharge end directed downward into the enclosure, 2. fan in said air intake, and means, in said air intake whereby the air is cleaned before it is delivered to said enclosure.

6. A spray cabinet comprising, in combination, an enclosure having an open side and having an outlet in one of its other sides, a combustion chamber located adjacent said outlet, a burner in said combustion chamber, a deflector plate located substantially centrally of said combustion chamber and adjacent the said burner and positioned substantially crosswise of the combustion chamber, and a suction fan at the discharge end of the combustion chamber.

7. In combination, a spray-booth and means for scavenging and fire treating paint ladened air from said booth; said means comprising a conduit which includes an exhaust pipe in communi cation with said booth; an enlargement connected in line of flow with said exhaust pipe; and a dis-' charge pipe beyond and in line of flow with said enlargement; means setting up flow of air from the booth through said exhaust pipe, enlargement, and discharge pipe; a burner discharging burning fuel into the enlargement in line of flow of air from the exhaust pipe into said enlargement; and a deflector in said enlargement receiving impingement of burning fuel from the burner and paint ladened air from the exhaust pipe; said deflector having a diameter not materially less than that of the communication between the exhaust pipe and the enlargement, but materially less than the internal diameter of the enlargement and leaving an air-flow and com bustion space between its perimeter and said enlargement.

8. A combination as set forth in claim '7, in which the diameter of the discharge pipe is materially less than the internal diameter or the enlargement, said discharge pipe is joined to the enlargement through means of an offset; and the deflector in the enlargement stands near said offset and forms with the latter a circuitous passage that promotes the commingling and combustion oi the fuel and the paint ladened air.

LUTHER E. BATES. 

